Carton



Oct. 28, 1958 o. L. VlNES ET AL CARTON 3 Sheets-Sheet 1 Filed Dec. 4, 1956 INVENTORS OSCAR L. VINES ROBERT A. H

BY ACKENBERG QMO-u8l- ATTORNEYS 1958 o. L. VlNES ET AL CARTON 5 Sheets-Sheet 2 Filed Dec. 4, 1956 INVENTORS OSCAR L. VINES A. HACKENBERG ROBERT BY ,Q MJ GM I ATTORNEYS Oct. 28, 1958 o. L. VINES ET AL 2,358,013

CARTON Filed Dec. 4, 1956 3 Sheets-Sheet 5 INVENTORS OSCAR L. VINES ROBERT A. HAGKENBERG BY r I 8m bhmt BW/7 n 22 '2 ATTORNEYS United States Patent 2,858,013 Patented Oct. 28, 1958 CARTON Oscar L. Vines, New York, N. Y., and Robert A. Hackenberg, Paramus, N. J., assignors to Continental JCompany, Ridgefield Park, N. J., a corporation of laew ersey Application December 4, 1956, Serial No. 626,191

9 Claims. (Cl. 206-4531) This invention relates to folding cartons. More particularly, it relates to a carton blank that can be folded and erected to form a six-sided carton having a transparent top wall.

When packaging merchandise for display and sale it is frequently desirable to employ a container having at least one transparent wall that will permit the merchandise packaged therein to be seen by prospective purchasers. One of the display containers commonly used for this purpose consists of a five-sided open top box or carton that is erected, filled with the merchandise and then wrapped with a piece of transparent sheet material such as cellophane. The wrapping of cellophane permits the contents of the display box to be seen while retaining the contents within the box. However, the separate operations of erecting the box, filling the box, and wrapping the filled box with cellophane add considerably to the expense of using such boxes. A large part of this expense is attributable to the separate step of wrapping the open top box with cellophane or similar material. In an effort to overcome this disadvantage, various carton constructions have been proposed wherein the carton is provided with a transparent top wall that formsan integral part of the carton 'blank. However, these one-piece display cartons have not met with wide acceptance because the added cost of manufacturing the one piece carton more than offsets any saving realized in erecting and filling the carton.

We have now developed a novel carton blank construction that is inexpensive to manufacture and that can readily be folded and erected from its original fiat condition to form a six-sided carton having a transparent top wall. Our novel carton blank is of unitary or onepiece construction in the sense that all of the various walls and other parts of the erected carton form integral parts of the original carton blank. That is to say, the transparent top wall of the carton forms an integral part of the original unitary carton blank, thus eliminating the necessity for a separate operation to apply an overwrapping of cellophane or similar material about the erected carton.

The unitary carton blank of our invention consists of an underlying layer of fibrous sheet material and an overlying layer of transparent sheet material affixed to the underlying layer adjacent the peripheral edges thereof, the two layers of sheet material forming a single, flat, composite piece adapted to be folded and erected to form a six-sided carton having a transparent top wall. The underlying layer of fibrous sheet material of the carton blank comprises a central panel, a pair of side wall panels connected to opposite longitudinal edges of the central panel along a first pair of longitudinally disposed fold lines, a pair of end wall panels connected to opposite lateral edges of the central panel along a pair of laterally disposed fold lines, and end closure means disposed at the ends of the fibrous sheet material adjacent each end wall panel. The layer of fibrous sheet material is further provided with a second pair of longitudinal fold lines one of which is disposed within each one of the pair of side wall panels intermediate one of the first pair of longitudinal fold lines and the adjacent longitudinal edge of the fibrous sheet material. In addition, the fibrous sheet material is provided with a pair of laterally disposed cut lines each extending across the central panel and into the adjoining portions of the said wall panels to connect the adjacent extremities of the second pair of longitudinal fold lines. The said pair of laterally disposed cut lines and the portions of the first pair of longitudinal fold lines disposed therebetween define a bottom wall portion of the centralpanel. Similarly, each one of the laterally disposed cut lines, the adjacent lateral fold line, and the portions of the first pair of longitudinal fold lines disposed therebetween define one of a pair of top wall portions of the central panel. The overlying layer of transparent sheet material is glued or otherwise fastened to the layer of fibrous sheet material along the peripheral edges thereof, and preferably along the said pair of top wall portions and the distal portions of the pair of side wall panels.

To erect the unitary carton blank of our invention and form a six-sided carton therefrom the two side walls are simultaneously folded upwardly about the first pair of longitudinal fold lines and downwardly about the second pair of longitudinal fold lines. The two end wall panels are then folded downwardly about the pair of laterally disposed fold lines, and the end closure means are fastened into place as will be hereinafter described to close the two ends of the resulting six-sided carton.

The carton construction of our invention will be more clearly understood from the following description in conjunction with the accompanying drawings of which Fig. l i a plan view of a preferred form of the unitary carton. blank of our invention;

Fig. 2 is a perspective view of the erected carton formed from the carton blank of Fig. 1;

Fig. 3 is a fragmentary plan view of one end of a modified carton blank of our invention;

Fig. 4 is a perspective view of the carton obtained by erection of the blank of Fig. 3;

Figs. 5, 7 and 9 are fragmentary plan views of one end of other modifications of our carton blank; and

Figs. 6, 8 and 10 are fragmentary perspective views of one end of the erected cartons obtained from the carton blanks of Figs. 5, 7 and 9, respectively.

As seen from the drawing, the unitary carton blank of our invention comprises an underlying layer of fibrous sheet material it such as paper board or cardboard to which is atfixed adjacent the peripheral edges thereof an overlying layer of transparent sheet material 11 such as cellophane or the like. The term unitary carton blank as employed herein thus refers to a blank formed from two or more pieces of fibrous sheet material and transparent sheet material glued or otherwise fastened together to form a single composite piece of these materials. The layer of fibrous sheet material 10 is formed with certain fold lines and cut lines hereinafter described that permit the sheet material to be folded and erected to form five sides of the six-sided carton of our invention. The overlying layer of transparent sheet material 11 is not formed with fold lines or cut lines corresponding to the fold and cut lines formed in the underlying layer of fibrous sheet material. However, because of the transparent nature of the overlying layer 11 the lines formed in the underlying layer 10 are shown clearly in the drawing, and consequently the reference numerals of the drawing are applied to these lines as though the. layer of transparent sheet material were not present.

In the preferred embodiment of our invention shown in Fig. 1 the layer of fibrous sheet material. 10 of the carton blank is provided with a central panel defined by i a pair of longitudinally disposed fold lines 12 and a pair of laterally disposed fold lines 13. The laterally disposed fold lines 12 extend from one end of the layer to the other. However, it will be noted that portions 12a of the fold lines 12 are displaced slightly outwardly and that portions 12b converge slightly inwardly at the ends of the layer 15. The purpose of the slight outboard displacemement of the portions 12a and the slight inward convergence of the portions 12b is merely to facilitate erection of the carton, and for puposes of the present discussion the portions 12a and 12b of each lateral fold line 12 will be consideredpart of one continuous laterally disposed fold line. Each of the pair of longitudinally disposed fold lines 12 is spaced an equal distance inboard from opposite longitudinal edges of the carton blank, and each of the pair of laterally disposed fold lines 13 is spaced an equal distance inboard of opposite lateral edges of the carton blank. The portion of the layer 10 disposed between the pair of lateral fold lines 13, one of the pair of longitudinal fold lines 12 and the adjacent longitudinal edge of the said layer 10 comprises one of a pair of side wall panels 15. Similarly, the portion of the layer 10 disposed between the pair of longitudinal fold lines 12 (or, specifically, the portions 12b of the fold lines 12), each one of said laterally disposed fold lines 13 and the adjacent lateral edge of the layer 10 comprise one of a pair of end wall panels 16.

The ends of the layer 10 adjacent the aforesaid end wall panels 16 are provided with end closure means which, when the carton is folded and erected, are adapted to maintain the ends of the erected carton in their closed condition. In the preferred embodiment of our carton each end Wall panel is provided with a tongue element or portion 17 that is connected to the main portion of the end wall panel by a lateral fold line 18, the tongue portion 17 having a lateral cut line 19 formed therein. Hook panels 20 formed with hook elements 20a are disposed at the four corners of the carton blank on both sides of the end wall panels 16. The hook panels 20 are connected to the adjacent side wall panels 16 by cut lines 21. The manner in which the hook panels 20 and the tongue portions 17 of each end wall panel 16 cooperate to form a rigid and securely fastened end wall closure will be described hereinafter.

Each side wall panel is provided with one of a second pair of longitudinally disposed fold lines 22 positioned approximately intermediate one of the first pair of longitudinal fold lines 12 and the adjacent longitudinal edge of the layer 10. A pair of laterally disposed cut lines 23 extend across the central panel of the layer 10 and into the adjoining portions of the two side wall panels to connect the adjacent extremities of the second pair of longitudinal fold lines 22. The lateral cut lines 23 are advantageously placed an appreciable distance inboard from the adjacent lateral fold line 13 of the pair of lateral fold lines, and each lateral cut line 23 is advantageously configured to provide a lip element or portion 24 adapted to be received in the aforementioned lateral out line 19 in the tongue portion 17 of the adjacent end wall panel.

The portion of the central panel disposed between the first pair of longitudinal fold lines 12 and the pair of lateral cut lines 23 comprises a bottom panel portion 26 of the central panel. Similarly, the portions of the central panel disposed between the portions 12a of the first pair of longitudinal fold lines 12, one of the pair of lateral cut lines 23 and the adjacent lateral fold line 13 comprise one of a pair of top panel portions 27 of the central panel. The layer of transparent sheet material 11 is glued (or otherwise fastened) along its peripheral edges to the underlying layer of sheet material 10. In the preferred embodiment of our carton the layer of transparent sheet material 11 is glued to the underlying layer 10 longitudinally along the distal edges of the two side wall panels 15 and laterally along the top panel por- 4 tions 27 of the central panel as shown by the speckled area 28 in Figs. 1 and 2 of the drawing.

To erect the carton as shown in Fig. 2, the two side wall panels 15 of the carton blank are simultaneously folded downwardly about the longitudinal fold lines 22 and about the portions 12a of the longitudinal fold lines 12, and upwardly about the portions of the longitudinal fold lines 12 disposed between the pair of lateral cut lines 23. As shown in the drawing, the lower portions of the resulting side walls 15 are of double thickness. Each end wall panel 16 is then folded downwardly about the adjacent lateral fold line 13 while at the same time the tongue portion 17 of the end wall panel is folded inwardly about the fold line 18 so that the lip portion 24 of the bottom panel will engage and enter the cut line 19 formed in the tongue portion 17. The hook panels 20 are then folded inwardly toward each other about the extended portion of the lateral fold line 13, and the hook elements 20a are engaged or hooked together as shown in Fig. 2. The engagement of the lip portion 24 in the cut line 19 prevents further inward movement of the end wall 16 while at the same time providing a firm connection between the bottom panel 26 and the end wall 16. Similarly, the mutual engagement of the hook elements 26a of the hook panels 20 prevents any outward movement of the end walls 16. The resulting end wall structure provides a rigid and secure closure for the two end walls of the erected carton.

As noted, the transparent layer 11 is glued to the layer 1% adjacent the distal edges of the two side wall panels.

Accordingly, when the two side wall panels are folded downwardly about the portions 12a of the longitudinal fold lines 12 the distal edges of transparent layer 11 is also folded downwardly about these portions 12a. The layer 11, however, is also glued to the top panel portions 27 and is not fastened in any way to the bottom panel 26. As a consequence the central portion of the layer 11 is supported by the top panel portions 27 and is separated from the bottom panel 26 when the carton is erected as described. The transparent layer 11 thus forms the transparent top wall of the erected carton. In its entirety the resulting carton comprises a bottom wall 26, two side walls 15 the lower portions of which are of double thickness, two end walls 16 held securely closed by the end closure means, and the aforementioned transparent top wall 11.

In the modification of our invention shown in Figs. 3 and 4, the carton blank of Fig. 3 is configured so that the erected carton is provided with upwardly and outwardly diverging side walls 15 as shown in Fig. 4. The carton blank is also provided with a different type of end closure means than the one previously described, and with modified side wall panels having longitudinal legs or spacers 30 on which the erected carton rests.

-To obtain a carton having side walls which diverge outwardly as shown in Fig. 4 it is necessary to make the bottom of the carton somewhat narrower than the top of the carton. Thus, the main portion of the longitudinal fold lines 12 which define the longitudinal edges (i. e. the width) of the bottom panel portion 26 are spaced somewhat closer together than the portions 12a of these longitudinal fold lines which define the longitudinal edges (i. e., the width) of the top panel portions 27 of the central panel. Moreover, the portions 12b of the longitudinal fold lines 12 which define the sides of the end wall panels 16 converge as shown in Fig. 3 so that the sides of the end wall panels will conform to the sloping side of the erected carton.

The modified end wall closure means at each end of the carton blank of Fig. 3 comprises a tongue portion 32 connected to the adjacent end wall panel 16 along a lateral fold line 33, a pair of hook elements 34 connected to the tongue 32 along longitudinal fold lines 35, and a pair of gusset elements 37 connected to the ends of the adjacent side wall panels 15 along an extension of the lateral fold sesame line 13 and to the sides of the adjacent end Wall panel 16 along the aforementioned longitudinal told line portions 121). Each gussetelement 37 is providedwith a diagonal fold line 3S-extendingfrom the adjoining corners of the adjacentrend wall panel 15 and side wall panel 16 outwardly atan angle of about 45. When anend wall panel 15:" of the cation blank is folded inwardly the associated gusset elements 37 also fold inwardly into the interior of the carton about the lateral fold line 13 and longitudinal fold line portions 12b, the diagonal fold lines 38 facilitating the inward folding of the gusset elements. At the same time that the end wall panel 16 and the associated gusset elements 37 are being folded inwardly into the interior of the carton, the hook elements 34 are simultaneously folded upwardly into the carton from below so that these hook elements become latched to the side wall panels 15 at the fold line 22, as shown clearly in Fig. 4 of the drawing. It will be noted that with the type of end closure means shown in Figs. 3 and 4 it is unnecessary to provide the bottom panel 26 with a lip 24 adapted to engage a corresponding slit in the tongue panel portion 32 of the end wall panel 16.

To provide the longitudinal legs or supports 30 for the erected carton, the outermost section or edge of each side wall panel 15 is made slightly wider or deeper than the inside section of this side wall panel. Accordingly, when the carton blank is folded and erected, the two side wall panels 15 are folded about the associated longitudinal fold lines 22 to form the aforementioned double thickness side walls of the carton the outer sections of which are provided with the longitudinal legs 30 shown in Fig. 4. The

carton blank shown in Fig. 7, and the erected carton shown in Fig. .8, are also provided with the aforementioned longitudinal legs 30.

In the modification of our carton blank shown in Fig. 5, the blank is configured so that it can be erected to form a carton having upwardly and inwardly converging sides as shown in Fig. 6. In addition, the carton blank of Fig. 5 is formed with still another type of end closure means than the two heretofore described, and the overlying layer of transparent sheet material 11 is secured to the underlying layer of fibrous sheet material in a somewhat different manner than that heretofore described.

To obtain a carton having side walls which converge inwardly slightly as shown in Fig. 6, it is necessary to make the bottom of the carton somewhat wider than the top of the carton. Accordingly, the main portion of the pair of longitudinally disposed fold lines 12 which define the longitudinal edges (i. e., the width) of the bottom panel are spaced somewhat farther apart than the portions 12a of these longitudinal fold lines which define the longitudinal edges (i. e., the width) of the top panel portions 27 of the central panel. Moreover, the portions12b of the longitudinal .fold lines 12 which define the sides of the end wall panels 16 diverge outwardly as shown in Fig. 5 so that the sides of the end wall panels will conform to the sloping sides of the erected carton.

The modified end closure means shown in Figs. 5 and 6 each comprise tongue portion 40 connected to the adjacent end wall panel 16 along the lateral fold line 41, a pair of integrally formed hook elements 42, and a pair of gusset elements .45 connected to the adjoining side wall panels 15 along extended portions of the lateral fold line 13 and to the adjoining end wall panel 16 along the aforesaid portions 12b of the longitudinally disposed fold lines 12. Moreover, each tongue portion 40 is formed with a lateral out line 43, and the adjacent lateral cut line 23 is configured to define a lip portion 44 slightly undercut at its lateral ends, the lip portion 44 being adapted to engage and enter the lateral cut 43wl1en the carton blank is folded and erected.

A rigid and securely fastened and closure is obtained when the carton is erected by folding the end wall panel 16 downwardly about the lateral fold line 13 while simultaneously folding the gusset elements 45 inwardly about fold lines 1211 and 13 and while folding the tongue portion 40 inwardly into the interior of the carton about the fold line 41. To facilitate the inward folding of the gusset elements 45 each gusset element is provided with a diagonally disposed fold line 46 extending outwardly from the adjoining corners of the side wall panel 15 and the end wall panel 16 at an angle of aproximately 45. As the end wall 16 moves toward its closed position the lip portion 44 of the bottom panel engages and enters the lateral cut line 43 formed in the tongue portion 40, and the hook elements 42 of the tongue portion slide underneath the inwardly folded gusset elements 45. When fully closed, the undercut ends of the lip portion 44 lock the said lip portion in place in the cut line 43, and the hook elements 42 snap over and become latched to the cars 47 formed in each gusset element for this purpose.

In the modification of Figs. 5 and 6 it will be seen that the central part of each lateral out line 23 coincides with the central part of the adjacent lateral fold line 13, thus eliminating the corresponding central part of the top panel portion 27 located therebetween. As a result, the lateral edges of the layer 11 of transparent sheet material are glued (or otherwise afiixed) to the end wall panels 16 and the associated gusset elements 45 rather than to the top panel portion 27 as hereinbefore described. This manner of attaching the layer 11 to the underlying layer 10 can be employed whenever the carton blank is provided with gusset elements at each of the four corners of the layer 10, as shown, for example, in Figs. 3 and 5. It should be employed whenever the top panel. portions 27 of the layer 10 are too small to provide an adequate base to which to fasten the edge of the layer 11, as shown, for example, in Pig. 5.

In the modification of our carton construction shown in Figs. 7 and 8, the carton blank is configured so that the two layers of the double thickness side walls 15 of the erected carton diverge at a slight angle so as to increase the rigidity of the side walls. The carton blank is also provided with still another form of end closure means.

As hereinbefore pointed out, each side wall panel 15 is folded about the associated longitudinal fold line 22 to form a side wall of the erected carton the lower portion of which is composed of a double thickness of the fibrous sheet material 10. The resulting double thickness side wall inherently possesses considerable strength and rigidity. The inherent strength and rigidity of the side walls of the erected carton can be made even greater by causing the two layers of sheet material forming the double thickness thereof to be disposed at a slight angle to each other.

As seen in Fig. 7, to accomplish this result, the portions of the pair of longitudinally disposed fold lines 12 which define the longitudinal edges of the bottom panel 26 are spaced somewhat closer together than the portions 12a of these longitudinally disposed fold lines which define the corresponding edges of the top panel portions 2'7. The configuration of the side wall panels and the central panel portions of the blank of Fig. 7 thus resemble these portions of the blank of Fig. 3. However, the end wall panels 16 of the blank of Fig. 7 differ from those of Fig. 3 in that the former are sub stantially rectangular rather than being tapered as described previousiy to conform to the sloping side walls of the erected carton. As a result, when the canton is erected the inner layer of each double thickness side wall 15 diverges downwardly and inwardly at a slight angle away from the vertically disposed outer layer of this side wall, thus contributing substantially to the strength and rigidity of the side wall 15.

The end closure means shown in Figs. 7 and 8 each comprises a tongue portion or element 50 connected to the adjacent end wall panel 16 along a lateral fold line 51, and a pair of closure panels 55 disposed on either side of the end wall panel and connected to the adjacent lateral edges of the side wall panels 15 along extensions of the adjacent lateral fold line 13 of the aforementioned pair of lateral fold lines 13. The tongue 50 is formed with a laterally disposed out line 52 located approximately in the center of the tongue, and with a pair of lateral cut lines 53 one of which is located at the opposite ends of the lateral fold line 51. The portions of the tongue 50 disposed adjacent each lateral out line 53 comprise hook portions 54 equivalent in function to the hook portions 42 shown in Fig. 5. The cut line 23 is configured to provide a lip portion 56 adapted to be received in the cut line 52 when the carton is erected.

To close the end of the erected carton, the closure panels 55 are first folded inwardly into the interior of the carton about the fold line 13, and then the end wall panel 16 is folded downwardly about the associated fold line 13 while the tongue 51 is simultaneously folded inwardly into the interior of the carton about the associated fold line 51. When fully closed the hook portions 54 of the tongue 50 snap over and engage the ears 57 formed in the closure panels 55 for this purpose. The resulting end wall construction shown in Fig. 8 provides a sturdy and secure closure for the carton of our invention.

In the modification of our carton blank shown in Fig. 9 the blank is configured so that the carton erected therefrom is provided with downwardly and inwardly converging or sloping end walls as shown in Fig. 10. The end closure means of Figs. 9 and 10 is essentially the same as that shown in Figs. 7 and 8. However, to permit the end wall panels 16 at each end of the blank to be folded inwardly so that the two end Walls of the carton converge as indicated in Fig. 10, a pair of longitudinally disposed cut lines 59 are provided one of which is located at each end of each lip portion 56 as shown best in Fig. 9. Thus, When the tongue 50 is folded into the carton the lip portion 56 will enter the lateral cut line 52 as hereinbefore described. However, due to the provision of the pair of longitudinal cut lines 59, the lower edge of the end Wall can be moved inwardly beyond its ordinarily vertical final position until it fits snugly against the said lip portion 56. It will be noted that in order to fold the closure panels 55 into the interior of the carton, the extensions 13a of the adjacent later fold line 13 must be disposed at an angle that conforms to the slope of the convergent end walls of the erected carton. The resulting end wall structure provides a neat, strong and rigid closure for the end of the carton.

It will be appreciated that, by appropriate modification of the carton blank, any of the various end-Wall closure means disclosed herein or closure means eqnivalent thereto or any of the various modifications in side wall construction disclosed herein can be used in combination with one another, the presently preferred combination of these features being the modification shown in Fig. 1.

From the foregoing description of our invention it is apparent that we have devised a novel unitary carton construction that is very inexpensive to manufacture and that can readily be folded and erected to form a sixsided carton having a transparent top wall. Accordingly, our novel carton blank constitutes an important improvement in the art to which it relates.

We claim:

1. A unitary carton blank adapted to be folded to form a six-sided carton having a transparent top wall, said carton blank consisting of an underlying layer of fibrous sheet material and an overlying layer of transparent sheet material afiixed to said underlying layer adjacent the peripheral edges thereof, said underlying layer of fibrous sheet material comprising a central panel, a pair of side wall panels hingeably connected to opposite longitudinal edges of said central panel along a first pair of longitu- & dinally disposed fold lines, a pair of end wall panels hingeably connected to opposite lateral-edges of said central panel along a pair of lateral fold lines, and end closure means disposed at each end of said fibrous sheet material adjacent each end wall panel, each of said pair of side wall panels being formed with one of a second pair of longitudinal fold lines the ends of which terminate an appreciable distance from the lateral edges of said side wall panels, said central panel and the adjoining portions of said pair of side wall panels being formed with a pair of laterally disposed cut lines each of which connects adjacent ends of said second pair of longitudinal fold lines, said central panel thereby being formed with a pair of top panel portions one each of which is located at opposite ends of the central panel between one of said pair of lateral fold lines and the adjacent laterally disposed cutline and with a bottom panel portion located between said pair of top panel portions, said end closure means being adapted to cooperate with said bottom panel portion when the carton blank is erected to maintain the carton blank in its erected condition, said overlying layer of transparent sheet material being aifixed to said underlying layer adjacent the remote longitudinal edges of said pair of side panel portions and the remote lateral edges of said pair of top panel portions.

2.'A unitary carton blank adapted to be folded to form a six-sided carton having a transparent top wall, said carton blank consisting of an underlying layer of fibrous sheet material and an overlying layer of transparent sheet material aflixed to said underlying layer adjacent the peripheral edges thereof, said underlying layer of fibrous sheet material comprising a central panel defined by a first pair of longitudinally disposed fold lines each spaced an equal distance inboard of opposite longitudinal edges of said sheet material and a pair of lateral fold lines each spaced an equal distance inboard of opposite lateral edges of said sheet material, a pair of side wall panels connected to opposite longitudinal edges of said central panel along said first pair of longitudinally disposed fold lines, a pair of end wall panels connected to opposite lateral edges of said central panel along said pair of lateral fold lines, and end closure means disposed adjacent said end wall panels, said fibrous sheet material being further provided with a second pair of longitudinal fold lines one of which is disposed in each one of said pair of side wall panels intermediate one of the first pair of longitudinally disposed fold lines and the adjacent longitudinal edge of the fibrous sheet material and with a pair of laterally disposed cut lines connecting the adjacent extremities of said second pair of longitudinal fold lines, said first pair of longitudinally disposed fold lines and said pair of laterally disposed cut lines defining a bottom panel portion of said central panel, and each of said pair of lateral fold lines, the adjacent laterally disposed out line and the portions of said first pair of longitudinally disposed fold lines extending therebetween together defining one of a pair of top panel portions of said central panel, said overlying layer of transparent sheet material being secured along its peripheral edge to the underlying layer of fibrous sheet material adjacent the distal edges of the two side wall panels and the distal edges of the two top panel portions.

3. A unitary carton blank according to claim 2 in which each fold line of said second pair of longitudinal fold lines is disposed closer to the adjacent fold line of said first pair of longitudinally disposed fold lines than to the adjacent longitudinal edge of the layer of fibrous sheet material whereby the distal edges of the pair of side wall panels are provided with longitudinally disposed leg portions.

4. A unitary carton blank according to claim 2 in which the end closure means at each end of the blank comprises a tongue element connected to the adjacent end wall panel along a lateral fold line, a pair of hook panels one of which is disposed on either side of the end wall panel and is connected to the adjacent side wall panel along an extended portion of the adjacent one of said pair of lateral fold lines, and a lip element formed in the adjacent lateral edge of said bottom panel portion of the central panel, said tongue element being formed with a laterally disposed cut line, said pair of hook panels being provided with cooperating hook elements adapted to be mutually engaged when the carton blank is erected, said lip element being adapted to be received in said lateral cut line formed in said tongue element when the carton blank is erected.

5. A unitary carton blank according to claim 2 in which the end closure means at each end of the blank comprises a tongue element connected to the adjacent end wall panel along a lateral fold line, a pair of hook elements one of which is disposed on either side of said tongue element and is connected thereto along a longitudinal fold line, and a pair of gusset elements one of which is disposed on either side of said end wall panel and is connected to said end wall panel along a longitudinally disposed fold line and to the adjacent side wall panel along an extension of the adjacent one of said pair of lateral fold lines, said hook elements and said gusset elements being adapted to fold into the interior of the carton when the carton blank is erected, said hook elements being further adapted to engage an upper edge of the adjacent side wall when the carton blank is erected.

6. A unitary carton blank according to claim 2 in which the end closure means at each end of the blank comprises a tongue element connected to the adjacent end wall panel along a lateral fold line, said tongue element being formed with a laterally disposed cut line and with a pair of laterally extending hook elements, a pair of gusset elements one of which is disposed on either side of said end wall panel and is connected to said end wall panel along a longitudinally disposed fold line and to the adjacent side wall panel along an extension of the adjacent one of said pair of lateral fold lines, and a lip element formed in the adjacent lateral edge of said bottom panel portion of said central panel, said lip element being adapted to be received in said lateral cut line formed in said tongue element when the carton blank is erected, said tongue element and said gusset elements being adapted to fold into the interior of the carton when the carton is erected, the pair of hook elements being adapted to simultaneously engage the inwardly folded gusset elements.

7. A unitary carton blank according to claim 2 in which the end closure means at each end of the blank comprises a tongue element connected to the adjacent end wall panel along a lateral fold line, said tongue element being formed with a laterally disposed cut line and with a pair of laterally extending hook elements, a pair of end closure panels one of which is disposed on either side of said end wall panel and is connected to the adjacent side wall panel along an extension of the adjacent one of said pair of lateral fold lines, and a lip element formed in the adjacent lateral edge of said bottom panel portion of said central panel, said lip element being adapted to be received in said lateral cut line formed in said tongue element when the carton blank is erected, said end closure panels and said tongue element being adapted to fold into the interior of the carton when the carton is erected, the pair of hook elements of said tongue element being adapted to engage the inwardly folded end closure panels to prevent withdrawal of said tongue element.

8. A unitary carton blank according to claim 2 in which the bottom panel portion of the central panel is appreciably wider than the pair of top panel portions of the central panel whereby the carton formed from the carton blank will have upwardly and inwardly converging side walls.

9. A unitary carton blank according to claim 2 in which the bottom panel portion of the central panel is appreciably narrower than the pair of top panel portions of the central panel whereby the carton formed from the carton blank will have upwardly and outwardly diverging side walls.

References Cited in the file of this patent UNITED STATES PATENTS 1,602,254 Schindler Oct. 5, 1926 2,118,821 Ringler May 31, 1938 2,638,210 Sparks May 12, 1953 2,744,622 Sparks H May 8, 1956 2,758,778 Arneson Aug. 14, 1956 FOREIGN PATENTS 615,490 Great Britain Jan. 6, 1949 

